SUNRPC: handle malloc failure in ->request_prepare

If ->request_prepare() detects an error, it sets ->rq_task->tk_status.
This is easy for callers to ignore.
The only caller is xprt_request_enqueue_receive() and it does ignore the
error, as does call_encode() which calls it.  This can result in a
request being queued to receive a reply without an allocated receive buffer.

So instead of setting rq_task->tk_status, return an error, and store in
->tk_status only in call_encode();

The call to xprt_request_enqueue_receive() is now earlier in
call_encode(), where the error can still be handled.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 8bf2af8546d2..3c7407104d54 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1858,6 +1858,9 @@ call_encode(struct rpc_task *task)
 	xprt_request_dequeue_xprt(task);
 	/* Encode here so that rpcsec_gss can use correct sequence number. */
 	rpc_xdr_encode(task);
+	/* Add task to reply queue before transmission to avoid races */
+	if (task->tk_status == 0 && rpc_reply_expected(task))
+		task->tk_status = xprt_request_enqueue_receive(task);
 	/* Did the encode result in an error condition? */
 	if (task->tk_status != 0) {
 		/* Was the error nonfatal? */
@@ -1881,9 +1884,6 @@ call_encode(struct rpc_task *task)
 		return;
 	}
 
-	/* Add task to reply queue before transmission to avoid races */
-	if (rpc_reply_expected(task))
-		xprt_request_enqueue_receive(task);
 	xprt_request_enqueue_transmit(task);
 out:
 	task->tk_action = call_transmit;